/Engine/Source/Runtime/Sockets/Public/SocketSubsystem.h
Checks the host name cache for an existing entry (faster than resolving again)
true if the host was found, false otherwise
bool GetHostByNameFromCache ( const ANSICHAR * HostName, [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< class [FInternetAddr](API\Runtime\Sockets\FInternetAddr) > & Addr )